Open Bug 1970327 Opened 1 year ago Updated 7 months ago

www.bilibili.com - "Always request desktop site" fails to return the desktop version of the page when activated

Categories

(Firefox for Android :: Browser Engine, defect)

Product:
Firefox for Android
Component:
Browser Engine
Platform:
ARM
Android
Type:
defect

Tracking

()

Project Flags:
Webcompat Score 1
Tracking Flags:
Tracking Status
firefox139 --- affected
firefox140 --- affected
firefox141 --- affected

People

(Reporter: rbucata, Unassigned)

References

(Blocks 1 open bug,
URL
)

Details

(Whiteboard: [webcompat-source:web-bugs][webcompat:sightline][webcompat:japan])

Attachments

(2 files)

12.06.2025_17.26.35_REC.mp4
3.08 MB, video/mp4
Details
Screenshot_2.png
235.47 KB, image/png
Details

Environment:
Operating system: Android 10
Firefox version: Firefox 139.0

Preconditions:
"Settings > Site settings > always request desktop site" enabled

Steps to reproduce:

  1. Navigate to: https://www.bilibili.com/
  2. Observe

Expected Behavior:
Desktop site instead of mobile site

Actual Behavior:
Mobile version received

Notes:

  • Reproduces regardless of the status of ETP
  • Reproduces in firefox-nightly, and firefox-release
  • Does not reproduce in chrome

Created from https://github.com/webcompat/web-bugs/issues/159808

This happens will all the URLs that I have tested, but I am not sure what might be the correct product and component to move this to, since it seems to be a browser bug, and not a webcompatibility bug.

status-firefox139: --- → affected
status-firefox141: --- → affected

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.

status-firefox140: --- → affected
Whiteboard: [webcompat-source:web-bugs] → [webcompat-source:web-bugs][webcompat:sightline]
Webcompat Score: --- → 1
Component: Site Reports → General
Keywords: webcompat:site-report
Product: Web Compatibility → Firefox for Android
Flags: needinfo?(calu)

Thanks for reporting. What device are you on? I'm testing on a Samsung s23 and am seeing the desktop version of https://www.bilibili.com/.

Flags: needinfo?(calu) → needinfo?(rbucata)

The Bugbug bot thinks this bug should belong to the 'Firefox for Android::Browser Engine' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Component: General → Browser Engine

As seen in the newly uploaded attachment, when the setting is activated, the desktop version is not returned, unless I specifically ask for the desktop version, from the browser option.

Tested with:

Operating System: Google Pixel 3 (Android 12) -1080 x 2160 pixels, 18:9 ratio (~443 ppi density)
Operating System: Oppo Find X5 (Android 13) - 1080 x 2400 pixels, 20:9 ratio (~402 ppi density)

Flags: needinfo?(rbucata)

The severity field is not set for this bug.
:boek, could you have a look please?

For more information, please visit BugBot documentation.

Flags: needinfo?(jboek)
Severity: -- → S4
Flags: needinfo?(jboek)
Whiteboard: [webcompat-source:web-bugs][webcompat:sightline] → [webcompat-source:web-bugs][webcompat:sightline][webcompat:japan]

This bug seems to appear every time when I click on a link which opens in a new tab.

Device: Firefox for Android 132, Android 10

Steps to reproduce:

  1. open "Settings > Site settings > always request desktop site"
  2. restart Firefox (to make sure the settings are applied)
  3. host this page on a local web server and open it in Firefox
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
</head>
<body>
<a href="">Link 1</a>
<a href="" target="_blank">Link 2</a>
<a href="javascript:window.open(window.location.href)">Link 3</a>
</body>
</html>
  1. click "Link 2" or "Link 3"
Flags: needinfo?(calu)

:rbucata, could you help me?

Flags: needinfo?(rbucata)

I am not familiar with hosting a page in a local web server, but I have tried to replicate the issue using the code provided, in codepen.io. The provided reduced test case works as expected in codepen.io, using the latest Nightly on Android devices (13-14), following the steps to reproduce. A new tab is opened when tapping on Link 2 or Link 3.

Notes:
New tabs are opened, regardless if "Settings > Site settings > always request desktop site" is enabled or not.

Flags: needinfo?(rbucata)

Yes, a new tab is opened as expected, but on my device the new tab is mobile site instead of desktop site. The font size is bigger in mobile site than in desktop site.

Browser:
Firefox nightly 2025-09-30-16-29-01, Android 10

Steps to reproduce:
Same as above

Expected:
The same page is opened in a new tab, with the same font size. (a desktop site)

Found:
The same page is opened in a new tab, with bigger font size. (a mobile site)

Flags: needinfo?(rbucata)

:rbucata, could you reproduce it?

I haven't used any bug trackers before. Shall I need to mention you every time, or shall I just need to wait?

In the new tab opened, using codepen, regardless of the desktop site option status, I do not see any differences in the font size.

Sorry for the late reply, but we are getting a lot of requests lately.

Flags: needinfo?(rbucata)
Attached image Screenshot_2.png —

:rbucata, sorry for wasting your time. The steps above aren't very clear, and here's a clearer version.

Browser: Firefox for Android nightly 2025-10-07-09-51-47, Android 10

Steps to reproduce:

  1. open "Settings > Site settings > always request desktop site"
  2. restart Firefox (to make sure the settings are applied)
  3. paste the html on codepen
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
</head>

<body>
Device Type: <b id="device-type"></b>
<br/>
<a href="">Link 1</a>
<a href="" target="_blank">Link 2</a>
<a href="javascript:window.open(window.location.href)">Link 3</a>
</body>

<script>
let deviceType = /Mobi|Android|iPhone/i.test(navigator.userAgent) ? "Mobile" : "Desktop";
document.getElementById("device-type").innerText = deviceType;
</script>
</html>
  1. get the direct link of the page
    (On my device I can't copy the link directly in the preview area, so I click "Link 2" and then copy the link in the address bar. Please close this page to avoid confusion.)
  2. open a new tab and paste the direct link into the address bar (we call this page P1)
  3. click "Link 2" or "Link 3" in P1 and another tab will be opened (we call this page P2)

(Codepen isn't nessesary, it can also be reproduced with a local web server)

Expected:
P1 is desktop site. P2 is desktop site. They have the same font size.
(because we opened "always request desktop site")

Found:
P1 is desktop site. P2 is mobile site. The font size is bigger in P2.

Flags: needinfo?(rbucata)

I get the same results. P1 is desktop site, P2 is mobile site.

Flags: needinfo?(rbucata)
Flags: needinfo?(calu)

I have reproduced it on the latest Nightly (2026-01-16).

:rbucata, Could you help me find someone to fix it? I have been waited for a long time.

Flags: needinfo?(rbucata)

We have different teams working across Firefox. I can't really have any input here, as a QA, unfortunately.

Flags: needinfo?(rbucata)
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